Well, good afternoon everybody. It is wonderful to be back. Secretary Panetta, thank you for the introduction. Last week at the White House we had our first Cabinet meeting since the election, and it was a chance for me to thank my entire team for their service; for keeping our country safe and strong these past four years. And, Leon, few have done more than you in that regard. And that includes taking care of our remarkable men and women in uniform and their families and keeping our military the absolute best in the world -- bar none. So thank you, Leon, for being such an outstanding Secretary of Defense. We're very grateful. (Applause.)

Now, I am not here to give a big speech. I wanted to just come by and join you in marking the 20th anniversary of one of the country's smartest and most successful national security programs: Nunn-Lugar. And I want to express my gratitude to all of you -- from government, academia, NGOs and our partners from around the world. People in this room conceived it. You built it. You've sustained it. And of course, I especially want to acknowledge a leader who helped create it and who now helps guide it as our outstanding Deputy Secretary of Defense -- Ash Carter. So thank you, Ash, for your great work. (Applause.)

Of course, no one has done more than the two visionaries on this stage. Now, you have to think about what real visionaries do. They look at the world and they see what's missing. So they set out to fill the gap; to build something new. And that's what Sam Nunn and Dick Lugar did many years ago. They challenged us to think anew; to imagine, after decades of confrontation, how our nations might engage in cooperation. Early in the Cold War, Einstein warned of the danger of our wisdom not keeping pace with our technology. And with Nunn-Lugar, our wisdom began to catch up.

I also wanted to be here because of my own personal debt to these two leaders. When I was in -- when I was elected to the Senate, Sam Nunn was one of the first leaders I called. Obviously, he had an extraordinary reputation for his work on a whole range of issues in the Senate. And, Sam, by the way, I should -- I always meant to say thanks for taking my call. (Laughter.) So we do small talk, he congratulates me on being elected. And then he says, I've got two pieces of advice for you. First piece of advice: Get a seat on the Foreign Relations Committee. I did that. Second piece of advice: Learn from Dick Lugar. (Laughter.) I did that, too. So I took Sam's advice then. And as President, I continue to value his advice and his counsel.

Sam, as one of the so-called "Four Horsemen" -- which I'd say is a pretty ominous nickname -- (laughter) -- has spoken out for a world without nuclear weapons. And with your Nuclear Threat Initiative, you helped us ratify the New START treaty, rally the world to secure nuclear materials, strengthen the global nonproliferation regime, and create an international fuel bank for peaceful nuclear power. Sam, that's an extraordinary legacy and an extraordinary record. Thank you for your partnership and your leadership. (Applause.)

And because I took Sam's advice, I came to know and admire Dick Lugar. I was a new, junior senator. But nevertheless, he was willing to take me in and served in many cases, particularly on the issues that we're celebrating here today, took me in as a pupil for him. I watched, and I learned. And when we worked together to pass a law to speed up the lockdown of nuclear materials, obviously it was called Lugar-Obama -- in that order. (Laughter.)

And, Dick, I want to take this opportunity to say something else. At times, we've disagreed on matters of policy. But one thing we've always shared is a notion of what public service should be. That it ought to be more than just doing what's popular in the moment. That it ought to be about what's right for our nation, over the long term. It ought to be about problem-solving and governance, not just how we can score political points on each other or engage in obstructionism. And where compromise is not a vice and where bipartisanship is a actually considered a virtue -- to be rewarded, not punished.

That's the essence of these two gentlemen, and that's the essence of Nunn-Lugar. That's the spirit that's defined Dick's public service for nearly 50 years. And that's the bipartisan tradition that we need more of here in Washington, especially on foreign policy. So, Dick, as you prepare to leave the Senate that you love, I think I speak on behalf of everybody here and millions of people across the country to say that your legacy will endure in a safer and more secure world, and a safer and more secure America. And we pray that this nation produces more leaders with your sense of decency and civility and integrity. We are grateful to you. Thank you very much. (Applause.)

Now, I will point out, it was Dick who took me on my first foreign trip as a Senator -- to Russia and Ukraine and Azerbaijan. We were there to see the Cooperative Threat Reduction program in action. And the first thing I learned is that when Dick Lugar travels overseas, it's not a junket. We didn't stop and look at a lot of beautiful sights -- (laughter) -- and sort of lounge around on some shopping excursions. He wore out every 25-year-old staffer that was part of this delegation.

What you also learn is that Dick Lugar -- the more remote the place is and the more obscure the facility is, the bigger a rock star Dick Lugar is. (Laughter.) I mean, they love him in these places.

I remember walking through one facility. I started leaning in for a closer look and one of the workers said, don't touch that orange stuff. It turned out to be TNT. (Laughter.) At another point, the workers were taking apart munitions -- gloves on their hands, masks over their faces -- and I'm thinking, wait a second, why don't we have masks on? (Laughter.) This is the kind of trip you take with Dick Lugar. (Laughter.)

We're traipsing through nuclear weapons storage sites and junkyards full of old land mines and technicians showing off test tubes where you said, well, what's that? Well, that's anthrax, that's plague. (Laughter.) Shouldn't you keep it in something a little more sturdy than this? (Laughter.) Dick Lugar is standing in the back of the room. (Laughter.) I remember I asked him, I think, have you seen it? He says, yes, yes, I've seen it. I don't get too close now. (Laughter.) That's what it's like traveling with Dick Lugar.

And I had been a strong advocate for CTR before. But visiting those facilities, seeing the work that so many of you do, seeing these old weapons once aimed at us now being turned into scrap truly brought home how important this work was. This is one of our most important national security programs. And it's a perfect example of the kind of partnerships that we need, working together to meet challenges that no nation can address on its own.

And so, Nunn-Lugar is the foundation for the vision that I laid out, once I was elected President, in travel to Prague -- where nations come together to secure nuclear materials, as we're doing with our Nuclear Security Summits, where we build on New START and continue to work to reduce our arsenals; where we strengthen the Nuclear Non-Proliferation Treaty and prevent the spread of the world's most deadly weapons; where, over time, we come closer to our ultimate vision -- a world without nuclear weapons.

That's why we haven't just sustained programs like Nunn-Lugar over the past four years. We've worked with all of you to strengthen it, expanding it to some 80 nations, far beyond the old Soviet Union -- moving ahead with the destruction of chemical weapons -- partnering with others, countries from Africa to Asia and global health organizations to prevent the spread of deadly diseases and bioterrorism. And I have to give a shout-out to somebody who was on the original team with Ash that conceived of CTR; she's been working it ever since and now leads our efforts at the White House -- Laura Holgate is here. And so we're very proud of her for the outstanding work that she's done. (Applause.)

And we've worked to keep weapons from spreading, whether it was nuclear material in Libya or, now, chemical weapons in Syria. And on Syria, let me just say this. We will continue to support the legitimate aspirations of the Syrian people --- engaging with the opposition, providing with -- providing them with the humanitarian aid, and working for a transition to a Syria that's free of the Assad regime.

And today, I want to make it absolutely clear to Assad and those under his command: The world is watching. The use of chemical weapons is and would be totally unacceptable. And if you make the tragic mistake of using these weapons, there where be consequences, and you will be held accountable. (Applause.)

We simply cannot allow the 21st century to be darkened by the worst weapons of the 20th century. And that's why, over the past four years, we've continued to make critical investments in our threat reduction programs --- not just at DOD, but at Energy and at State. In fact, we've been increasing funding, and sustaining it. And even as we make some very tough fiscal choices, we're going to keep investing in these programs --- because our national security depends on it.

After all, even with all your success --- the thousands of missiles destroyed, bombers and submarines eliminated, the warheads that have been deactivated --- we're nowhere near done. Not by a long shot. And you all know this. There's still much too much material --- nuclear, chemical, biological --- being stored without enough protection. There are still terrorists and criminal gangs doing everything they can to get their hands on it.

And make no mistake, if they get it, they will use it; potentially killing hundreds of thousands of innocent people, perhaps triggering a global crisis. That's why I continue to believe that nuclear terrorism remains one of the greatest threats to global security. That's why working to prevent nuclear terrorism is going to remain one of my top national security priorities as long as I have the privilege of being President of the United States.

So, I came here in part to say we cannot let our guard down. This needs to be a sustained effort across all your organizations, across our government. We have to keep investing in our people and in new technologies. We have to sustain the partnerships we have, and that includes Russia.

We're joined by some of our Russian friends today. Russia has said that our current agreement hasn't kept pace with the changing relationship between our countries. To which we say, let's update it. Let's work with Russia as an equal partner. Let's continue the work that's so important to the security of both our countries. And I'm optimistic that we can.

And we have to keep creating new partnerships. We have to make sure --- to paraphrase Einstein --- that our wisdom stays ahead of our technology. And I know you're committed to this. And I want you to know that I am, too.

So let me leave you with a story of that first trip Dick and I took together. You may remember this, Dick. I was Ukraine. We went to a facility, an old factory. We walked down these long, dark corridors. We're ducking our heads, stepping over puddles of -- something -- we're not sure what it was. (Laughter.) Finally, we came across some women, sitting at a worktable. On it were piles of old artillery shells. And the women were sitting there, taking them apart. By hand. Slowly. (Laughter.) Carefully. (Laughter.) One by one.

It took decades --- and extraordinary sums of money --- to build those arsenals. It's going to take decades --- and continued investments --- to dismantle them. The two of you know know this better than anybody. It's painstaking work. It rarely makes the headlines. But I want each of you to know, and everybody who's participating in this important effort to know, that the work you do is absolutely vital to our national security and to our global security.

Missile by missile, warhead by warhead, shell by shell, we're putting a bygone era behind us. Inspired by Sam Nunn and Dick Lugar, we're moving closer to the future we seek. A future where these weapons never threaten our children again. A future where we know the security and peace of a world without nuclear weapons. I could not be prouder of these gentlemen. I'm proud to call them friends. And I'm looking forward to continuing to work with them and all of you in the years to come.